Inverted T-shaped endstops for reclosable package

ABSTRACT

A length of flanged zipper material for reclosable packages or bags is provided with inverted T-shape endstops wherein the zipper profiles are crushed and the flanges are fused together. The reclosable packages or bags are separated at the mid-point of the inverted T-shaped endstops thereby forming L-shaped and reversed L-shaped endstops. The zipper flanges are fused together in the lower cross elements of the endstop thereby providing an area for the slider to be placed wherein the forces from distension of the package or bag walls are unlikely to exert forces to separate the slider from the zipper. This is particularly applicable to slider zippers wherein the flanges are attached to or substantially co-planar with the exterior sidewalls of the interlocking elements of the zipper profiles.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to reclosable packages or bags and theslider zippers used in the construction thereof. More particularly, thepresent invention relates to reclosable packages, and slider zippersused in the construction thereof, wherein the flanges of the sliderzipper are attached to, or are in the same plane as, the outside facesof the zipper profile and wherein inverted T-shaped endstops are formedon lengths of zipper material, thereby resulting in L-shaped endstops atthe ends of the zipper segments.

2. Description of the Prior Art

In the prior art of reclosable packages or bags for consumer goods,slider operated zippers are well-developed and satisfactory for theirintended purpose in many ways. Typically, the zippers for suchreclosable packages or bags are constructed and arranged so that theflanges of the zipper are inwardly offset from the exterior sidesurfaces of the reclosable interlocking profiles of the zipper (see FIG.1). This provides a horizontal surface for the feet of the slider toengage securely, making it difficult to force the slider from theprofiles, even when the sides of the package or bag are distended so asto force the zipper open.

However, if the zipper includes flanges which are co-planar with thereclosable interlocking profiles (see FIG. 2), or if the flanges areattached to the outside of the zipper profiles, forces which distend thepackage or bag will tend to force the slider from the profiles,particularly when the sides of the package or bag are distended so as toforce the zipper open.

OBJECTS AND SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide areclosable package or bag, and the zipper used in the manufacturethereof, wherein the zipper flanges may be co-planar or attached to theoutside of the zipper profiles, while maintaining a secure engagement ofthe slider to the zipper when the sides of the package or bag aredistended so as to tend to force the zipper open.

This and other objects are attained by forming inverted T-shapedendstops on a length of flanged zipper material at package-widthintervals (or intervals corresponding to the desired length of thesubsequent zipper segment). The length of zipper material wouldsubsequently be separated at the mid-point of the T-shaped endstops toprovide zipper lengths for individual packages or bags.

The slider is inserted onto the zipper profile, typically either beforeor during manufacture of the reclosable package or bag. When the packageor bag is open, the slider can be retracted to a position above thecross element of the endstop, thereby preventing or minimizing theprying forces of the package or bag walls against the slider.

DESCRIPTION OF THE DRAWINGS

Further objects and advantages of the invention will become apparentfrom the following description and claims, and from the accompanyingdrawings, wherein:

FIG. 1 is a cross-sectional view of a prior art slider zipper whereinthe flanges are inwardly offset from the exterior side surfaces of thereclosable interlocking profiles of the zipper.

FIG. 2 is a cross-sectional view of a prior art slider zipper whereinthe flanges are attached to the exterior side surfaces of the reclosableinterlocking profiles of the zipper, illustrating how the distension ofthe package or bag walls can pry the slider from the zipper.

FIG. 3 is a side plan view of a length of zipper material wherein aseries of the inverted T-shaped endstops are formed prior to theinsertion of the sliders.

FIG. 4 is a side plan view of a length of zipper material wherein aseries of the inverted T-shaped endstops are formed. Sliders are alsoillustrated, which may be inserted before or after the formation of theinverted T-shaped endstops.

FIG. 5 is a side plan view of the length of zipper material with aseries of inverted T-shaped endstops, sealed to film or web for theformation of reclosable packages or bags.

FIG. 6 is a side plan view of two adjacent reclosable packages or bags,subsequent to the separation of the packages or bags at the mid-point ofthe inverted T-shaped endstops.

FIG. 7 is a side plan view of a single reclosable package or bag,illustrating the slider positioned above the cross element of theendstop, thereby shielding the slider from the force of the distensionof the package or bag walls.

FIG. 8 is a top view of the single reclosable package or bag illustratedin FIG. 7.

FIG. 9 is a plan view of an alternative embodiment of the reclosablepackage or bag wherein the slider plow abuts the endstop.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings in detail, wherein like numerals indicatelike elements throughout the several views, one sees that FIG. 1 is aview of a prior art zipper 500 comprising first and second interlockingprofiles 502, 504, including respective first and second interlockingelements 506, 508 and first and second flanges 510, 512. First andsecond flanges 510, 512 are sealed to respective first and second walls(not shown) of a reclosable package (not shown). Slider 514 includes topwall 516 and downwardly extending sidewalls 518, 520 which terminate inrespective inwardly extending engaging feet 522, 524. First and secondflanges 510, 512 are inwardly offset from the respective exterior sidefaces 530, 532 of respective interlocking elements 506, 508 so that whenthe filled reclosable package (not shown) is opened thereby urging thefirst and second flanges 510, 512 into the illustrated distended angle,the feet 522, 524 of the slider 514 remain engaged to the respectivefirst and second interlocking elements 506, 508 of the zipper 500.

In FIG. 2, however, the first and second flanges 510, 512 are attachedto the respective exterior side faces 530, 532 of the respective firstand second interlocking profiles 502, 504. In this configuration,opening the filled reclosable package urges the first and second flanges510, 512 into the illustrated distended angle, so that the feet 522, 524of the slider 514 can be pried and separated form the first and secondinterlocking elements 506, 508 of the zipper 500.

FIGS. 3 and 4 illustrate a length of flanged zipper material 10 with aseries of inverted T-shaped endstops 100, 102, 104. Length of flangedzipper material 10 includes first and second interlocking profiles 12,14 with respective first and second interlocking elements 16, 18 andrespective first and second flanges 20, 22 as is known in the prior art.

Inverted T-shaped endstops 100, 102, 104 are formed in the length offlanged zipper material 10 at package length intervals, or at least atintervals corresponding to the desired length of the subsequent zippersegment. The inverted T-shaped endstops 100, 102, 104 include respectivestems 110, 112, 114 (perpendicular to the first and second interlockingelements 16, 18) and respective lower cross elements 120, 122, 124(parallel to and separated from first and second interlocking elements16, 18) and are formed by an inverted T-shaped anvil and/or horn (notshown) which, in the area of the stems 110, 112, 114 crushes the firstand second interlocking elements 16, 18 of the respective first andsecond interlocking profiles 12, 14 and fuses the first and secondflanges 20, 22 together. In the lower cross elements, the first andsecond flanges 20, 22 can be fused together by a series of dimples asillustrated in lower cross elements 120, 122, or can fused together in aseries of fuse lines as illustrated in lower cross elements 124 of FIG.3. The leftward lower cross element 124 of FIG. 3 is illustrated withvertical fuse lines while the rightward lower cross element 124 isillustrated with horizontal fuse lines. However, it is envisioned thatthe lower cross elements could be fused together with fuse lines goingin any direction or with a large number of equivalent fuse linepatterns.

FIG. 3 is illustrated without sliders 130. FIG. 4 is illustrated withsliders 130 which may be inserted before or after, or even substantiallysimultaneously with, the formation of inverted T-shaped endstops 100,102, 104.

FIG. 5 illustrates length of zipper material 10, with the sliders 130inserted and the front and rear package or bag walls 140, 142 attachedto respective first and second flanges 20, 22. Bottom seal 198 attachesthe bottom edges of package or bag walls 140, 142 to each other.Alternatively, a fold may be substituted for bottom seal 198 wherebyfront and rear package or bag walls 140, 142 are formed from a singlesheet of web or film. The configuration of FIG. 5 is typically done aspart of a form-fill-and-seal (FFS) manufacturing process, but isadaptable to other manufacturing processes for reclosable packages.

FIG. 6 illustrates adjacent reclosable packages or bags 200, 202 whichare formed by separating or cutting the length of zipper material 10 andattached package or bag walls 140, 142 of FIG. 5 at package-widthintervals at the mid-point of inverted T-shaped endstops 100, 102, 104(thereby forming an L-shaped endstop and a reversed L-shaped endstop oneach segment of zipper 10) and forming vertical side seals 204, 206,208, 210 between the front rear package or bag walls 140, 142.

FIGS. 7 and 8 illustrate the individual package or bag 200 with theslider 130 toward the end of the zipper 10, positioned above the lowercross element 122. As the front and rear package or bag walls 140, 142are fused together in the lower cross element 122, any separation ordistension of the package or bag walls 140, 142, such as due to theopening of the package or bag 200 (see FIG. 8) will not exertsignificant prying forces on the slider 130 to separate the slider 130from the zipper 10.

FIG. 9 illustrates an alternative embodiment wherein slider 130 includesseparating plow 131 which abuts against the inner vertical face of lowercross element 122 when slider 130 is in the rightmost position. Thisadditional contact significantly increases the force required to pullslider 130 from the end of the zipper in the horizontal direction.

Thus the several aforementioned objects and advantages are mosteffectively attained. Although preferred embodiments of the inventionhave been disclosed and described in detail herein, it should beunderstood that this invention is in no sense limited thereby and itsscope is to be determined by that of the appended claims.

What is claimed is:
 1. A length of zipper material for reclosablepackages or bags, including: first and second interlocking profilesincluding respective first and second interlocking elements andrespective first and second bag wall engaging flanges, wherein the firstand second bag wall engaging flanges are attached to an exterior of therespective first and second interlocking elements, whereby the first andsecond bag wall engaging flanges are configured and arranged to connectthe first and second interlocking elements to respective first andsecond bag walls; at least one slider mounted on the first and secondinterlocking elements; a plurality of endstops formed on the length ofzipper wherein a portion of the first and second interlocking profilesare fused together, the endstops having the shape of an inverted T;wherein the shape of the inverted T includes a stem perpendicular to theinterlocking elements and at least one cross element parallel to theinterlocking elements; wherein the stem includes a portion where thefirst and second interlocking elements are crushed; wherein the at leastone cross element is immediately below a lower surface of the slider andincludes at least a portion wherein the first and second bag wallengaging flanges are fused together at a position separated from andbelow the interlocking elements thereby minimizing prying forces on theslider when a load is exerted on the first and second bag wall engagingflanges.
 2. The length of zipper material of claim 1 wherein the lengthof zipper material is separated into zipper segments at the mid-point ofthe endstops thereby providing a first separated endstop in the shape ofan L at a first end of the zipper segments and a second separatedendstop in the shape of a reversed L at a second end of the zippersegments.
 3. The length of zipper material of claim 2 wherein the zippersegments are separated into zipper segments at package-width intervals.